Clozapine and Fluvoxamine interaction
Clozapine and Fluvoxamine: both prescribing labels describe an interaction that usually calls for monitoring, a dose change, or spacing the doses.
Usually manageable with monitoring or a dose change. Tell your pharmacist you take both.
What the FDA labels say
From the Clozapine (Clozaril) label · effective 2025-06-06
• Concomitant use of Strong CYP1A2 Inhibitors: Reduce CLOZARIL dose to one-third when coadministered with strong CYP1A2 inhibitors (e.g., fluvoxamine, ciprofloxacin, enoxacin).
CYP1A2 Inhibitors Concomitant use of CLOZARIL and CYP1A2 inhibitors can increase plasma levels of clozapine, potentially resulting in adverse reactions.
Reduce the CLOZARIL dose to one-third of the original dose when CLOZARIL is coadministered with strong CYP1A2 inhibitors (e.g., fluvoxamine, ciprofloxacin, or enoxacin).
The CLOZARIL dose should be increased to the original dose when coadministration of strong CYP1A2 inhibitors is discontinued [see Dosage and Administration ( 2.7 ), Clinical Pharmacology ( 12.3 )] .
Moderate or weak CYP1A2 inhibitors include oral contraceptives and caffeine.
From the Fluvoxamine (fluvoxamine maleate) label · effective 2026-04-23
Clozapine: Clozapine levels may be increased and produce orthostatic hypotension or seizures ( 5.8 ).
Since clozapine-related seizures and orthostatic hypotension appear to be dose related, the risk of these adverse events may be higher when fluvoxamine and clozapine are coadministered.
Patients should be closely monitored when fluvoxamine maleate and clozapine are used concurrently.
Clozapine: See Warnings and Precautions ( 5.8 ) .
CNS Active Drugs Antipsychotics: See Warnings and Precautions ( 5.2 ) .
Taking more than these two? Interactions stack. Check your whole list at once; it stays in your browser.
Open in the checkerNot medical advice. Interaction Checker quotes FDA label text and NIH fact sheets. Whether an interaction matters for you depends on doses, timing, kidney and liver function, and other conditions. Confirm with a pharmacist or prescriber.